This is a note to let you know that I've just added the patch titled can: cc770: Fix stalls on rt-linux, remove redundant IRQ ack to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-cc770-fix-stalls-on-rt-linux-remove-redundant-irq-ack.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f4353daf4905c0099fd25fa742e2ffd4a4bab26a Mon Sep 17 00:00:00 2001 From: Andri Yngvason <andri.yngvason@xxxxxxxxx> Date: Wed, 14 Mar 2018 11:52:56 +0000 Subject: can: cc770: Fix stalls on rt-linux, remove redundant IRQ ack From: Andri Yngvason <andri.yngvason@xxxxxxxxx> commit f4353daf4905c0099fd25fa742e2ffd4a4bab26a upstream. This has been reported to cause stalls on rt-linux. Suggested-by: Richard Weinberger <richard@xxxxxx> Tested-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Andri Yngvason <andri.yngvason@xxxxxxxxx> Cc: linux-stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/cc770/cc770.c | 15 --------------- 1 file changed, 15 deletions(-) --- a/drivers/net/can/cc770/cc770.c +++ b/drivers/net/can/cc770/cc770.c @@ -447,15 +447,6 @@ static netdev_tx_t cc770_start_xmit(stru stats->tx_bytes += dlc; - - /* - * HM: We had some cases of repeated IRQs so make sure the - * INT is acknowledged I know it's already further up, but - * doing again fixed the issue - */ - cc770_write_reg(priv, msgobj[mo].ctrl0, - MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES); - return NETDEV_TX_OK; } @@ -684,12 +675,6 @@ static void cc770_tx_interrupt(struct ne /* Nothing more to send, switch off interrupts */ cc770_write_reg(priv, msgobj[mo].ctrl0, MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES); - /* - * We had some cases of repeated IRQ so make sure the - * INT is acknowledged - */ - cc770_write_reg(priv, msgobj[mo].ctrl0, - MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES); stats->tx_packets++; can_get_echo_skb(dev, 0); Patches currently in stable-queue which might be from andri.yngvason@xxxxxxxxx are queue-4.15/can-cc770-fix-use-after-free-in-cc770_tx_interrupt.patch queue-4.15/can-cc770-fix-queue-stall-dropped-rtr-reply.patch queue-4.15/can-cc770-fix-stalls-on-rt-linux-remove-redundant-irq-ack.patch